Author: Annemieke Groenenboom
A healthy lifestyle can prevent approximately one-third of cancer cases. Furthermore, it improves the quality of life during and after cancer treatment. However, permanent lifestyle change remains a significant challenge for many.
Evelyn Monninkhof (UMC Utrecht) and Renate Winkels (WUR) are researching the relationship between exercise and nutrition in cancer. In doing so, they can make good use of each other’s expertise, as well as that of sociologists and technologists.
Evelyn Monninkhof and Renate Winkels will talk about these pressing topics during our Lunch & Learn lecture, on February 15. See more information here.
What is the relationship between lifestyle and cancer?
1 in 2 people in the Netherlands develop cancer, and the numbers are rising. The increase is due to an aging population, increased screening, but certainly also due to unhealthier lifestyles. Lifestyle-related cancer types, such as skin, colon, and breast cancer, are particularly on the rise. However, the degree of influence varies depending on the type of cancer.
I focus on breast cancer (and exercise) because that’s my specialization. 1 in 7 women face a breast cancer diagnosis. A healthy lifestyle can prevent around 25-30% of breast cancer cases and improve the quality of life during and after treatment. Alcohol, overweight, and physical activity are the most influential lifestyle factors. For example, each additional glass of alcohol per day increases the risk of breast cancer by 7%, while sufficient physical activity reduces the risk of the disease by 20-40%.
Hormonal factors also play a role. As a woman, you often have little control over them, except after menopause. The ovaries no longer produce hormones at that stage. However, fat cells do. The more fat cells, the higher the hormone levels, and the higher the risk of breast cancer. This is where lifestyle (maintaining a healthy weight) comes into play again.
How does exercise contribute to prevention?
Exercise is good, but the more exercise, the better. The guideline is to engage in at least 150 minutes of moderate-intensity or 75-100 minutes of high-intensity exercise per week, spread across different days. In addition, strength training should be included at least twice a week. This is the advice for preventing breast cancer, but it’s also often recommended for reducing symptoms during and after treatment. Many women experience fatigue, anxiety, and/or depressive symptoms, reduced physical functioning, and/or ‘chemo brain’ (impaired memory, multitasking ability, and concentration) during that time.
As the treatment and symptoms become more specific, so does the exercise program. For example, there is strong evidence that individuals with mental health issues benefit more from endurance training than from strength training. That’s why we are increasingly focusing on personalized approaches .
Even though scientists have long demonstrated the relationship between exercise and cancer, it remains inadequately recognized by the general public. Awareness is far from as widespread as it is for smoking and lung cancer, let alone everyone acting upon it. This is due to a lack of education, but also due to facilitating factors such as insurance coverage. If exercise were a pill, it would have been covered by insurers long ago. The major challenge, therefore, is: how do you encourage people to engage in lasting, regular exercise?
How can other researchers contribute?
I see significant value in fostering greater collaboration with psychologists and technologists. By combining medical knowledge with expertise in behavior modification and technological innovations, we can make exercise more appealing and break unhealthy habits.
Additionally, I’m keen on collaborating more with other lifestyle researchers because it ultimately comes down to the whole picture. For instance, those who exercise more may develop increased appetite, so how do you adjust your diet to avoid gaining weight? We’re already working with WUR, but there might be room for expansion. This could lead to even better advice and aid in recruiting participants for trials.
Another common lifestyle-related cancer type is colorectal cancer. What is the relationship here?
In particular, colorectal cancer is strongly related to lifestyle. Here, we observe a significant association with alcohol and overweight. Nutrition also plays an important role. The risk decreases with limited consumption of red and processed meats and with sufficient intake of vegetables, fruits, and fibers.
My focus lies primarily on the effect of lifestyle interventions during and after cancer treatment, aiming to reduce the impact of side effects. WUR has a substantial cohort of colorectal cancer patients, with about 25% experiencing long-term cancer-related fatigue that cannot be alleviated by more sleep. In this cohort, we have found that fatigue may be linked to an unhealthy lifestyle. Currently, we are conducting intervention studies with a control group to examine whether a healthy lifestyle can alleviate these symptoms.
How can a healthy diet help these patients?
The general dietary guidelines apply here as well, with advice becoming more specific depending on the treatment and symptoms. Particularly during chemotherapy, the impact of lifestyle interventions can differ because chemotherapy affects your entire system. It’s aimed at targeting (metastatic) cancer cells but can also cause damage in other parts of your body.
We are researching whether and how the emphasis in dietary advice can be shifted for different types of cancer. A crucial question in this regard is: what do you want to achieve with these interventions, from weight loss to preventing cancer recurrence? This is often too specific for patients to figure out on their own. By the end of 2024, we hope to present the results of our intervention research. In the meantime, we are collaborating with the World Cancer Research Fund on www.voedingenkankerinfo.nl, where patients can find answers to all their questions.
How can other researchers contribute?
It would be interesting to investigate, possibly in collaboration with the Julius Center, how nutrition and exercise, as well as other lifestyle factors such as sleep and stress, influence each other. Does the combination have an even greater effect? However, this can be challenging because if nutrition and exercise have individual effects and only a slightly enhanced effect when combined, it would require large, complex studies. The smaller the improvement, the larger the study must be to demonstrate the effect. An intriguing question for technologists in the EWUU Alliance is: how can we make efficiency gains in monitoring nutrition and exercise?
Another challenge we face is how to engage an adequate number of participants for our trials. And how do we ensure that we reach not only the highly educated individuals with an interest in health? After all, that could skew the results. We are making efforts to make participation appealing to everyone, such as organizing patient days, but it’s challenging to capture people’s interest and commitment. What’s in it for them??
During the research, for instance, we offer free guidance from a dietitian, but the goal is for participants to continue afterward. That’s when health insurers need to cover it, but are they willing to? Moreover, this raises other questions: healthcare is already stretched thin, can it handle more? E-health can assist, but who will provide the guidance? In summary, there are plenty of intriguing challenges for all partners in the EWUU Alliance.
Lunch & Learn lecture: Reducing the impact of cancer through permanent lifestyle changes Want to know more about the research of Evelyn Monninkhof and Renate Winkels? Or do you see opportunities for collaboration? During our free online Lunch & Learn session, they will elaborate on their research and there will be plenty of room for ‘matchmaking’. Register here for the Lunch & Learn session on February 15, 2024.